South African police are searching for three men who forced a family from their car and drove off with a four-year-old boy hanging out of the vehicle.

The boy was later found dead in the abandoned vehicle.

Police are offering a reward of nearly 5,000 US dollars (£3,000) for information leading to arrests in the case, which has shocked South Africans accustomed to a high crime rate.

South African media say the boy was with his sister and parents in Boksburg, east of Johannesburg, during the carjacking Saturday night.

His mother told The Star newspaper that her son's foot got stuck as she tried to pull him from the car, but the carjackers sped off. The boy's head and body may have hit the road as the car sped away, causing fatal injuries.